A variety of types of valves exist, including ball valves, butterfly valves, gate valves, choke valves, and check valves. The suitability of these types of valves for a particular application may depend, for instance, on the environment in which the valve will operate and/or the desired performance characteristics of the valve. Check valves are a type of non-return valve that allow fluid (e.g., a liquid or a gas) to flow in only one direction. Check valves are commonly used in a variety of industries and for a variety of applications, including industrial and domestic applications.
Conventional check valves include a body, a cover, a hinge, and a disc connected to the hinge. The disc is configured to move between an open position and a closed position in which the disc forms a seal with the seat of the body. However, many conventional check valves have discs that are configured to spin about their axes relative to the hinge, which renders these conventional check valves unsuitable for certain industries and applications. For instance, American Petroleum Institute (API) Standard 594 requires that the discs of check valves be restricted from rotating 360 degrees. Rotation of the disc relative to the hinge may cause the disc to prematurely wear, creating a misalignment of the disc and thereby creating a leak path between the disc and the seat of the body.
Additionally, API Standard 594 requires all of the components of the check valve in contact with the process fluid to have at least the same corrosion resistance as the body of the check valve. Conventional check valves that utilize fasteners (e.g., a nut, a washer, and a cotter pin) to secure the disc to the hinge, may not satisfy, or may have difficulty satisfying, this standard. For instance, it may be expensive, time-consuming to manufacture, and/or difficult to procure components, such as nuts, washers, and cotter pins, having at least the same level of corrosion resistance as the body of the check valve.